S D 



CXj 



DEPARTMENT OF AGRICULTURE 



FOREST PRODUCTS LABORATORY 



REPORT PREPARED FOR 

THE COMMISSION OF THE UNITED STATES OF AMERICA TO 

THE BRAZIL CENTENNIAL EXPOSITION 




For Distribution at the Brazil Centennial Exposition 
1922-1923 



WASHINGTON 

GOVERNMENT PRINTING OFFICE 

1922 



DEPARTMENT OF AGRICULTURE 



FOREST PRODUCTS LABORATORY 



Supplementing Exhibit 

of the 

UNITED STATES FOREST SERVICE 

at (he 

BRAZIL CENTENNIAL EXPOSITION 

Rio de Janeiro, Brazil 

1922-1923 



V 



By 
HERBERT A. SMITH 

United States Forest Service 



1 V '^ 



LlHfV^RY OF CONGRESS f 

JAN 2319^'* I 



FOREST PRODUCTS LABORATORY 



A BKIlvF ACCOl'XT OF ITS WORK AND AIMS. 

The Forest IVoducis Lal^oralory is a unit in the Branch of Research of 
the I'orcst Service, I'nited States Department of Agriculture. It is 
located at Madison, Wis., and is conducted in cooperation with the 
University of Wisconsin. 

For several years after its establishment, in 1910, it was the onlv 
institution of its kind in the world conducted with the object of turning 
the searchlight of research upon wood and its uses and making the infor- 
mation thus obtained available to the public. 

PUBLIC SERVICE. 

SCOPE OF ACTIVITIES. 

The purjKJse of the Forest Service in the administration of the Forest 
Products Laboratory is to conserve American forests by developing the 
most economical methods of converting standing trees into Imished prod- 
ucts. The purpose is also to make the growing of timber more profita- 
ble by increasing the possibilities in the utilization of both used and 
unused species. The Laboratory seeks to develo]) not only new and more 
efficient processes, but to fmd ways of utilizing material which would 
otherwise be wasted, to find new uses for old materials and new materials 
for old uses. In a word, the aim is to render practical assistance to the 
manufacturers and users of wood and wood products and at the same time 
lo promote forest conservation and the practice of forestrv. 

Kvery American industry and class of consumers which uses or grows 
wood or any other i)roduct of the forest may thus be a beneficiary of the 
work done at the Laboratory. Every such industry, class of consumers, 
and timber {producers is a potential cooperator in the Laboratory's work. 
Its objects are sought not only through experiments conducted at the 
Laboratory but also through the detail of its men to work on important 
problems in the mills and factories and the receiving of representatives of 
the industries at the Laboratory to work beside its scientific men. 

\AI.rE OF WORK. 

The value of this work has already made itself apparent. The reduc- 
tion of waste, the better utilization of the products of the tree, the utiliza- 
tion of species hitherto wasted, the. added life given to many kinds of 

3 



4 FOREST PRODUCTS LABORATORY. 

wood products by more efficient preservative methods, the reduction of 
the degrade in kmiber by efficient dry-kiln methods, and many other 
savings are an enormous help in conserving the timber supply. 

RESULTS AVAILABLE TO PUBLIC. 

The value of the Forest Products Laboratory to any particular wood- 
using industry or class of consumers depends to a very large extent upon 
the use which that industry makes of it. It is a Government institution 
supported mainly by Government appropriations, and its advice and 
suggestions are to be had for the asking. It presents an opportunity for 
every manufacturer, user, and timber grower to supplement the informa- 
tion obtained by experience and hard knocks with technical data obtained 
through scientific research. 

PLACE IN FOREST CONSERVATION. 

The work of the Laboratory is of direct value to those engaged in 
timber production. To a ver}" large extent the kinds and sizes of forest 




trees which should be grown and the purposes for which they should be 
produced are dependent on the mechanical, physical, and chemical proper- 
ties of their wood and the uses to which they can most profitably be put. 
In the administration of the National Forests and of privately owned 
timberlands, in the activities of the State forestry depaitments, and in 
the instruction given by the forest schools the results secured by the 
Laboratory play an important part. By reducing the present waste of 
three-fourths of every tree cut and making possible the most efficient 
utilization of the one-fourth used they are contributing in a very essential 
way to forest conser\'ation and to profitable timber production. Through 
its forest products research the Forest Service supplements its efforts to 
bring about the growing of timber by information which should make 
possible the most complete and eflfective utilization. 



FOREST PRODUCTS LABORATORY. 5 

ORGANIZATION FOR RESEARCH. 

COORDINATED RESEARCH. 

Research is increasingly effective in proportion as it is carefully planned 
and executed. At the beginning of each year a program covering as nearly 
as practicable the work of the Laboratory for the ensuing year is con- 
sidered and approved. Individual initiative and responsibility are given 
the widest possible opportunity, but at the same time the work of different 
men is so coordinated by an interchange of ideas among the different 
sections, and other means, that duplication is avoided and cumulative 
results are obtained. 

ORGANIZATION OF THE LABORATORY. 

The Laboratory is in charge of a director, an assistant director, and a 
staff comprised of the heads of the different research and administrative 
sections. In each section are men of broad general experience with wood 




and knowledge of its characteristics, and other specialists in various wood 
uses, who devote their whole time to the study of special problems. These 
men are recruited, in accordance with the regulations of the Civil Service 
Commission, from the professions of engineering, chemistry, forestry, and 
pathology. 

The work of the Laboratory is distributed among the following technical 
sections : 

Timber mechanics. — Strength of wood and manufactured articles. 

Timber physics. — Experimental and applied kiln drying, physical prop- 
erties, identification, and structure of wood. 

Wood preservation. — Wood treatments, glues, and laminated construc- 
tion. 

P^llp and paper. — Manufacturing methods and suitability of various 
woods for pulp, paper, and special products. 

Derived products. — Chemical properties and uses of wood and chemical 
wood products, such as turpentine, alcohol, acetic acid, etc. 



6 FOREST l'R(JDUCTS I.ABORATOKV. 

Jn(lnslrial iiivcstigafKnts. — -Methods and ])ractices in the lumber and 
oiher wood-using industries, grades, specifications, and mill scale studies. 

Pathology (in cooperation with the Bureau of Plant Industry). — ^Decay 
ol" timber, molds, stains in manufactured wood products, and antiseptic 
j)ropertics of wood preservatives. 

TLMHKR MECHANICS. 

Knowledge of the mechanical properties of woods and wood products is 
essential for their intelligent and economic use, whether in the factory, on 
the farm, in the home, on the railroad, in the mine, or in the air. Thus 
development of the air])lane and progress in many other lines depend 
in a large measure on accm-ate information as to the strength, toughness, 
elasticity, and other mechanical properties which determine the suitability 
of dilTerenl woods for various ])urj)Oses. To supplv this information, over 
5(x),(X)o mechanical tests have l)een made, as nearly as possible under 
slandardi/x'd conditions, so that the tests made for a single purpose will 
have the broadest application and will serve for nian\' uses. 

STKICXCTII OF \'.\RIOUS SPFCIFS. 

1 )ala from tests of small clear specimens are now available in i.s" s])ecies 
of woods grown in the United vStates, as well as data, in some cases 
meager, in some cases fairlv complete, on abcnit 60 species, principally 
from South America and the Philippines. These data are of particular 
value in comparing the properties of the different species, in linding 
substitutes for the scarcer and higher-priced woods, in selecting species 
for particular uses, and in establishing correct working stresses. The 
results of these tests on small clear specimens also furnish definite 
information on the variabilitv of wood and show the necessit\' of grading 
timlx-r for all uses where strength is of prime im|)ortance. 

A large mnnbor of tests lia\e also been marie on full-sized timbers, 
such as bridge stringers, factorx-building timlx-rs, and car sills. These 
tests have demonstrated tlie inHuence of defects, such as kiK^ts, shakes, 
and checks, on strength; and, altogether with the results of tests on small 
clear specimens, furnish the basis for the estal)lishment of grading rules 
and correct working stresses for structural timl)ers. 

Tests have been made on plywood to determine the strength of different 
combinations of species, the etTect of increasing the lumiber of plies, and 
the elTect of varying the ratio of core thickness to total panel thickness. 
vSome data are also available on factors affecting warping, on strength 
of fastenings for plywood, on the elTiciency of joints in plywood, and on 
the strength in tension. Information on such points as these places the 
Laboratory- in a position to assist users and mamifacturers of plywood 
and veneer products in solving problems encountered in developing new 
uses lor these i)roducts in tlie various industries. 



FOREST PRODUCTS LABORATORY 




The largcsl of iht tc-blins inacliiues. shown here in the process of erection, is capable of exc-i ting a t 
million pounds and can test to destruction wooden columns 30 feet long and a foot square. 



FOREST PRODUCTS LABORATORY. 




The drum testing machine, developed by the Laboratory to simulate the hazards of transportation, has 
become standard lor shippers, packers, ;ind manufacturers. The boxes shown are packed with electric- 
hglit buhjs. Four thousand doUars' worth ol bulbs were furnished by the electric companies concerned 
for this series of tests to develop a better container. 



FOREST PRODUCTS LABORATORY. 




SoiiM 1 i I 1 u ugih-testing machines, such as the one at the right, are employed chiefly in determining 
the strength properties of native woods, using small, clear specimens like those on the truck. Other 
machines are rigged up to test wooden parts. A newly designed airplane wing rib is just being placed in 
the machine second in line. 

11958—22 2 



lO 



FOREST PRODUCTS LABORATORY. 




Furniture and vehicle faetunes are concerned ui the research ol the Laboratory to reduce losses in 
the steam bending of stock. To beud a hea\->- wheel rim, such as is shown, without fracture, requires 
a careful preliniinar\- conditioning^ treatment. 



FOREST PRODUCTS LABORATORY. I I 

TESTS ON SHIPPING CONTAINERS. 

The results of tests on containers are of particular interest to all 
shippers, box manufacturers, and transportation companies, and are 
also of great importance to the public in general. The damage due to the 
failure of containers in transportation amounts annually to many 
millions of dollars. There are, in addition, large losses due to improper 
packing. All of the work done at the Laboratory in this held tends 
directly to reduce these enormous losses, which are ultimately paid by 
the consumer. A considerable amount of fundamental data relating 
to the construction of boxes and crates has been obtained which fmds 
direct application in the redesign of faulty containers and in the develop- 
ment of new containers. It is frequently possible to redesign a container 
so as to reduce the amount of material required, to save shipping and 
warehouse space, and at the same time to obtain greater serviceability. 

DRUM TESTS. 

Rev(jlving-drum tests, together with drop and compression tests of 
boxes loaded with either actual or dummy contents, have been used in 
determining the characteristic weakness of the various types of con- 
tainers. The Forest Products Laboratory standard drum is 14 feet in 
diameter and can accommodate packages up to 1,000 pounds in weight. 
It is fitted with hazards so arranged that the container under test follows 
a regular cycle of droj^s which simulate those received in actual trans- 
portation. The field lor this work is very large, and much remains to be 
done in order to develop fundamental relations between the weight and 
the nature of the commodity, the type of box to be used, and the thick- 
ness of the bottom, side, and end boards. 

TKSTS OF MA.MJFACTURIil) ARTICLlvS. 

Tests on vehicle and implement parts, airplane parts, doors, and other 
articles manufactured of wood are made ]:)rimarily to demonstrate the 
fitness of substitute species, to develop or improve designs, and to obtain 
more economical and efficient use of wood. The limitations and possibili- 
ties of splices and laminated constructi(m are l)eing studied with a \iew 
to conserving lumber through the increased use of small pieces and low- 
grades. This should make possible the use of smaller trees, which can 
be grown in comparatively short periods, in short, the character of 
material on which the country will have to depend very largely in the 
future and which can be grown most profitably. 



12 FOREST PRODUCTS LABORATORY 







TIMBER PHYSICS. 

KILN DRYING. 

A knowledge of the physical properties of wood is of importance to 
almost every industry using wood and is essential in kiln drying, impreg- 
nation with preservatives, distillation, and other treatments. These 
physical properties include density, shrinkage, transfusion of moisture, 
hygroscopicity, specific heat, heat conductivity, heat of absorption of 
water in wood, and permeability of wood by liquids and gases. 

It is often necessary for financial reasons to reduce the time required 
properly to season wood by open-air drying. Moreover, for many pur- 
poses it is desirable to dry the wood more thoroughly than is possible in 
the open air and to employ conditions which will reduce its hygroscopicity, 
or tendency to shrink or swell. For these reasons dry kilns are almost 
universally employed for high-grade lumber, and frequently even for the 
poorer grades. In the drying of hardwoods it is estimated that about 
ID per cent of the material dried is either ruined or lowered in grade. 
Much of this loss could be avoided by proper methods and kilns, and the 
present results might be greatly improved in other respects. 

ESTABLISHING SCIENTIFIC PRINCIPEES. 

The Forest Products Laboratory bases all its kiln-drying practice on 
fundamental studies to determine the principles underlying the trans- 
fusion of moisture through wood, the effect of changes in atmospheric 
conditions upon the rate of transfusion, the effect of various methods of 
drying and of various drying treatments upon the properties of the wood 
being dried, and similar studies. 

DRYING SCHEDULES. 

A comprehensive series of experiments is being conducted to determine 
the proper "drying schedules" for all important commercial woods. 
These drying schedules will show the proper conditions of temperature 



FOREST PRODUCTS LABORATORY. 



13 



. i f I n r 

I J [ r 

/ T 

» r 




The distinctive feature of the Forest Service water-spray kiln is the control of the humidity in the kiln 
and, consequently, the drying rate of the lumber, by conditioning the air with sprays of water whose 
temperature is carefully regulated. The experimental kiln shown is drying oak bolster stock, which 
appears white because of the end dip used to reduce checking. 



14 



FOREST PRODIJCTS lyABOKATORY. 



and humidity to obtain best results in drying, and they will cov^er the 
entire range from an absolutely green condition to absolute dryness. A 
number of drying schedules have alread}- been published. This class 
of work has direct application throughout the wood-using industries. 

STEAM BENDINt;. 

The proj)er steam bending of heavy wooden parts, such as artillery 
wheel rims, presents a number of problems on which the Laboratory has 
done a limited amoimt of work and on which it plans to do much more 
in the near future. The proper moisture condition of the stock, the 
length and temperature of steaming or other jjreliminary treatment, and 
the mechanical details of the actual bending must all be worked out 
before i)rescnt high losses in this process can be overcome. 

IDENTIFICATION. 

The accurate identification of woods is important not only in the in- 
vestigative work of the Laboratory, where it is essential that the kind of 
wood under test be definitely known, but to wood users generally. 
There is a steadily increasing demand in the various industries for serv- 
ice of this character, and several thousand sj^ecimens of wood are an- 
nually identified for outside concerns. Microscopic slides and photo- 
inicrograjjlis made from the slides have been prepared for practically all 
American woods of im|)ortance and are available for study. Authentic 
specimens of most sjHcies are also available. 




WOOD PRESERVATION. 



PRESERVATIVES. 

The amount of wood in the form of railroad ties, mine timbers, posts, 
poles, and other products which is destroyed each year by decay is 
estimated at from one-half to three-quarters of a billion cubic feet. 
It is therefore important to devise methods of treating wood with pre- 
servatives that will reduce this waste to a minimum. 



FOREST I'konrCTS LAHOKATORV 



15 




In the manufacture ol ualci -resistant plywood with casein glue, the glue is applied cold to the 
veneer sheets by means cif a mechanical glue spreader. The sheets are then placed one on top 
of another in a press. 



i6 



FOREST PRODUCTS LABORATORY. 




The life of railroad ties treated with preservatives is often double that of untreated ties. The 
illustration shows some red-oak ties about to undergo an experimental treatment with creosote 
in the pressure cylinder. Afterward^; they will be placed in actual service in one of the test 
tracks maintained by the railroads in cooperation with the Laboratory 



IfOREST PRODUCTS LABORATORY. 1 7 

In treating operations, the cost of the preservative, such as creosote, 
zinc chloride, or sodium fluoride, amounts to a high percentage of the 
total cost. Furthermore, the ultimate success of any treatment is 
largely dependent upon the preservative used. Much information has 
already been obtained concerning the preservatives now in common 
use, but there is need for a great deal of further study with the object 
of developing new preservatives which will either be cheaper or more 
effective than present preservatives or will have properties fitting 
them for wider use or for special purposes. The value of a preservative 
is not considered established until it has had a thorough trial under 
actual service conditions. 

GLUES FOR PLYWOOD. 

In connection with the manufacture of plywood, studies have been 
made of animal glues, such as those made from hide, bone, and other 
products; and standard methods of testing have been developed. A 
suitable "standard glue" for aircraft work and high-class joint work in 
general has been selected and samples made available to manufacturers 
and users. This is the glue adopted as standard by Army and Na\y 
aircraft bureaus. 

The development of water-resistant glues of several types, including 
casein glues and blood-albumin glues, has been progressing for several 
years, and a number of high-grade glues have been perfected. Tests 
and experiments are being carried forward to improve these glues still 
more, especially in their resistance to moisture. 

LAMINATED AND BUILT-UP PARTS. 

One of the lines of investigation to be taken up recently is the deter- 
mination of possibilities and best practices in the design and construction 
of structural members built up of small pieces glued together. These 
investigations were carried out intensively on aircraft parts, such as 
wing beams and struts, when the success of the aircraft program was 
threatened by a sudden shortage of suitable material in the required 
sizes. The knowledge gained is being applied to extensive investigations 
of the use of laminated and built-up construction in the various wood- 
using industries for the manufacture of such articles as shoe lasts, hat 
blocks, bowling pins, wagon bolsters, and wheel hubs. 

The Laboratory has done considerable work on the moisture resistance 
of various wood coatings, and a very efficient aluminum leaf coating has 
been developed which affords protection against moisture over long 
periods of storage. Tests are now in progress on the durability of these 
coatings. Other work on wood finishes is contemplated. 



i8 



FOREST PKODl'CTS I,.\K(»KATOKV 




PULP AND PAPER. 

The constantly decreasing supply of suitable pulp woods and the 
ever-increasing demand for paper of all kinds, especially newsprint 
paper, have combined to produce so serious a situation that investiga- 
tions into methods of conserving the supply of pulp wood and increasing 
the production of paper are of paramount importance. 

PROCESSES OF PULP AND PAPER MAKINc;. 

The Laboratory is conducting experiments on methods of making 
wood pulp and has already developed several important improv^ements 
in the standard chemical processes. 

A very important field of research lies in determining the suitability 
of various little-used w'oods as substitutes for those most commonly used. 
Practically all available species which give promise of suitability are 
being investigated, and proper methods of grinding or cooking of most 
of the important ones have already been worked out. 

UTILIZATION OF WASTE. 

vStudies of waste utilization in the pulp and paper industry have been 
in progress for some time along a number of distinct lines. For example, 
feasible methods of turning sawmill waste, such as slabs, into pulp have 
been determined. The use of a certain percentage of spent tanbark in 
the manufacture of roofing felts has been investigated and a method 
developed whereby what was formerly a waste of the tanning industry 
is now in profitable commercial use. The possibility of using hemlock- 
bark waste for tannin has also been demonstrated. 

A commercially feasible method of recovering both the paraffin and 
the fiber from waxed paper trimmings has been developed. Studies of 
the wastes incident to tlie pulp industries, such as sulphite waste liquors 
and soda liquors, in which are now carried off approximately half of the 
wood that enters into the digesters, are to be undertaken intensively as 



FOREST PRODUCTS LABORATORY 



19 




Wooden patterns for castings can be made practically moisture proof by an alurauiuni icat coaung uud 
so prevented from warping, swelling, or shrinking. Car-wheel patterns protected in this way are 
now in use by several large foundries. 



20 



FOREST PRODUCTS LABORATORY. 




Old newspapers can be de-inked by the use of bentonite, a highly colloidal clay, to which the ink 
particles adhere after being loosened from the paper in the pulp beater. The pulp is then ready to 
be used again in the manufacture of news paper. 



FOREST PRODUCTS LABORATORY. 21 

soon as funds and equipment become available. The suitability for 
paper making of hull fiber and second-cut cotton linters, formerly of 
little value, has been demonstrated and a method of preparation worked 
out that has proved commercially successful. 

PULP DECAY. 

A recently begun investigation of the deterioration of pulp wood and 
wood pulp through fungous infection, now estimated at $5,000,000 a year, 
is leading to the proper remedies for this great economic loss. 




DERIVED PRODUCTS. 

HARDWOOD DISTILLATION. 

The distillation of hardwoods for the production of wood alcohol, 
acetate of lime, and charcoal offers one of the best methods for the utiliza- 
tion of hardwood wastes, such as tops, limbs, and slabs. The first work 
of the Laboratory along this line was a study of the comparative value of 
different species as distillation woods — at that time only beech, birch, 
and maple were used commercially. All the important hardwoods have 
been tested, and several new species, such as oak and hickory, are now in 
use. 

Methods have been developed whereby the yield of alcohol and acetate 
can be considerably increased by a system of temperature control with- 
out extending the time of distillation and with a decrease in the amount 
of fuel required. These methods have been adopted by most of the 
commercial plants. Encouraging results have been obtained in work 
now under way on other methods for increasing the yields, such as the 
treatment of the wood with chemicals previous to distillation. 

The production of flotation oils from hardwood tar is a promising 
method of utilization which has been the subject of much investigation 
of the Laboratory. Several satisfactory flotation oils have been pro- 
duced, and the commercial utilization of hardwood tar is increasing. 



2 2 FOREST PRODUCTS LABORATORY. 

TURIM-;.\TI.\i: AND ROSIN. 

Very \aluable results have been obtained by experimental field work 
in improving methods of obtaining crude turpentine from the tree. A 
new method has been de\ eloped which has increased the yield of turpen- 
tine and decreased the bad effect on the tree and reduced the danger from 
lire. This method has been adopted by almost the entire industry. A 
complete study has also been made of the amount and composition of 
the turpentine from several western pines. The changing conditions in 
this industry due to the rapid depletion of virgin stands of long-leaf pine 
make it desirable to develop turpentining methods which are especially 
apj)licable to second-growth timber and to long-continued operation on 
the same tree, instead of the usual three to five year operations. 

ETHVL (GRAIN) ALCOHOL- 

A promising method of utilizing profitably large quantities of wood 
waste depends upon the conversion of the cellulose into ethyl alcohol. It 
has long been known that wood cellulose can be converted into ferment- 
able sugar b}^ suitable treatment with dilute acids at high pressures, but 
until recently the process has not met with commercial success. Inves- 
tigation at the Laboratory involved the design and installation of appa- 
ratus of semicommercial size and a detailed study of the influence of such 
variables as pressure, temperature, time concentrations of acid and 
water, and many others. Partly as a result of these experiments the 
process is now a commercial success and offers a new means of utilization 
which will be a source of heat and power of immense economic importance. 
The two plants now operating in this country have a combined daily 
capacity of about 9,000 gallons of 95 per cent alcohol. The high quality 
and purity of the j^roducts are attested by the great demand for this 
alcolK>l for the jireparation of ])harmaceuticals and colognes. 

SAWDTST FOR STOCK FOOD. 

Another study that has recently been started is the production of a 
stock food from sawdust. As in the manufacture of ethyl alcohol, the 
cellulose is first converted into sugar by treatment under pressure with 
dilute acid, and this sugar, after being extracted and boiled down to a 
thick molasses, is mixed with the sawdust residue. This so-called "wood 
meal" has been substituted for one-fourth the ordinary grain ration of 
the cattle, with a resulting increase in their weight and no decrease in 
the yield of milk. 

OTHER DKRIVIvD PRODUCTS. 

Other products derived from trees or forest materials, and therefore 
within the scope of the Laboratory's work, are tannins, gums, balsams, 
essential oils extracted from the wood, roots, bark, or leaves of various 



FOREST PRODUCTS LABORATORY. 



23 




Aside irom its value in laboratory tests, the determination of the moisture content oi wood is so impor- 
tant in connection with the various uses of wood that every wooi %vorking factory should become 
familiar with the simple process. A knowledge of the moisture content of the stock often makes it 
possible to avoid costly manufacturing difficulties. 



24 



FOREST PRODUCTS LABORATORY 





Special small-scale digesters for the manufacture of chemical pulp provide facilities for the study of 
pi:lping problems at a moderate cost, preliminary to a cooperative mill test. 



FOREST PRODUCTS I.ABORATORY. 25 

trees, and producer gas manufactured from wood. The chemical deriv- 
atives of cellulose, while not yet touched upon, also offer a fertile field 
for investigation. 




INDUSTRIAL LWESTIGATIONS. 

MECHANICAL UTILIZATION OF WASTE AND LOW-GRADE MATERIAL- 

Mechanical as well as chemical processes offer a promising field for 
the profitable utilization of wood now wasted and for the steadily 
increasing amount of small and low-grade material coming from second- 
growth stands. Only 30 per cent of the wood in a forest now gets into 
the form of seasoned, unplaned lumber. Of this, an additional 10 to 25 
per cent is lost in the process of manufacture. In extreme cases as little 
as 3 per cent of the wood in the forest may reach the finished product. 

SURVEY OF WOOD WASTE. 

How to reduce to a minimum these losses in logging and manufacture 
constitutes a research problem of far-reaching scope and significance. 
The Laboratory has undertaken a comprehensive survey of the present 
practice and its results in some of the more important wood-using 
industries. This will be followed by more intensive investigations of 
equipment, methods, and processes with a view to determining possible 
modifications and improvements. These investigations will be con- 
ducted both in the woods and at the mill and will include studies leading 
to increased efficiency of operation as well as to closer utilization. 

DIMENSION STOCK. 

The manufacture of small-dimension stock offers a striking example 
of the opportunity for reducing present wastes in manufacture. It has 
been estimated that all of the five or six billion board feet used each 
year in the manufacture of articles made from such stock could be 
secured from material now wasted. Whether or not this is true, there 
is no question that present wastes could be greatly reduced by standard- 



FOREST l'K(^DUCTS LABORATORY. 







The first step in tlie manufacture of cattle food from sawdust is to cook the sawdust with dilute acid 
in a steam-prcssurc cylinder. ^ This converts a part of the wood into sugars and renders the remainder 
more digestible Hydroli/cd sawdust is being succcssliillv fed t<i cattle .is a ccmsidorable part of their 
.•■.mccntrate ration. 



FOREST PRODUCTS LABORATORY 




With a microscope il is possiljlc to identify wood irmn practically any of our native trees. Th 
revolving chart shows the diversity in w<Hid structure brimyht out inider a lens. 



28 



FOREST PRODUCTS LABORATORY. 



izing dimension sizes, by cutting dimension stock directly from the log 
instead of remanufacturing it from lumber, and by an interchange 
between industries that would result in the utilization by one industry 
of what is now regarded as waste in another. »Studies along these lines 
have been undertaken by the Laboratory and will be extended as rapidly 
as possible. 

SECOND-GROWTH STANDS. 

Another problem of first importance has to do with finding a profitable 
and economical use for the small sizes and low grades on which we shall 
have increasingly to depend as the virgin forests are replaced by second- 
growth stands. This problem includes also the finding of uses for species 
now without markets. To a considerable extent the practice of forestry 
is dependent on developing methods by which the material of all species 
produced by these stands can be used in place of the high-grade material 
of a few species from virgin forests to which we have hitherto been 
accustomed. This involves not only perfecting the technique of built-up 
and laminated construction, but the introduction of new uses and new 
methods of manufacture. Investigation of these and related problems 
will go far toward enabling us to eliminate present wastes and to make 
the most of our wood supply. 




PATHOLOGY. 

The work of this section is conducted by the Bureau of Plant Industry 
of the Department of Agriculture. General studies of the durability and 
decay of wood are carried on. 

DURABILITY OF UNTREATED WOOD. 

The relative durability of different woods and the effects of moisture 
and wood-destroying fungi upon the life of the wood have been studied 
for many kinds of American woods. Data have been obtained upon the 
least and most favorable temperatures for the growth of fungi and the 
amount of heat required to stop their growth. An application of this 
work is the control of so-called "drv rot" in buildings. 



FOREST PRODUCTS LABORATORY 



29 



DECAY IN BUILDING TIMBER. 

Extensive investigations to determine the prevalence of decay in 
buildings throughout the United States have been made, and from in- 
formation collected over a lo-year period recommendations have been 
developed as to changes in architectural design, proper species for 
different uses, and suitable antiseptic treatments. 

SANITATION OF STORAGE YARDS. 

Unsuspected losses by wood users resulting from improper storage of 
wood aggregate several million dollars annually. Studies and recom- 
mendations have been made on storage of general lumber stocks at 
sawmills and retail yards, the storage of manufactured wood products, 
such as vehicle parts, boxwoods, veneers, and staves, and also the storage 
of pulp wood and pulp. Infection begun in the yard frequently is 
passed on in the manufactured product to other wood with which the 
infected material is used. 




HOW TO USE THE LABORATORY. 

INFORMATION FREE. 

The Laboratory, being a public institution, makes its information 
available to the public as rapidly as possible. This it does through 
personal contact and through reports written during the progress of 
investigation and upon their completion, so that all information of value 
is published, either as bulletins or circulars by the Government, in 
technical notes, by correspondence, or as special articles in trade journals 
and technical and scientific papers. 

Investigations are undertaken both independently and on a coopera- 
tive basis, but all investigations must be of a research character that will 
give information or results of value in attaining the general objects aimed 
at by the Laboratory-. 



30 



FOKHST I'KODT'CTS LABORATORY. 




Classes in bi^xin^ iiul crating at the Laboratoi ^ ._, . .^l drum testiny machine to 

investigate the serviceabihty of shipping boxes. The manufacturers ami sliippers in the groiip^ 
traveled an average ol 3,000 miles each to attend the one- week course 



FOREST PRODUCTS LABORATORY. 3 1 

COOPERATION. 

As a general rule, no investigation conducted by the Laboratory is 
regarded as complete until the results obtained experimentally have been 
checked on a commercial scale and their industrial application deter- 
mined. This is ordinarily accomplished through cooperation with in- 
dividuals or companies that use wood and are commercially interested 
in developing new or better processes or products. 

FORMAL COOPERATION AT EXPENSE OF COMPANY. 

In cases of formal cooperation, there should be a remuneration to the 
Laboratory depending on the cost of the work done for the cooperator, 
including the time and expense of the members of the Laboratory de- 
tailed to the project, and its general supervision. When practically all 
of the work proposed is investigative and the results of value chiefly to 
the general public, the charge to the cooperator may be comparatively 
low or eliminated altogether. 

CONSULTATION ON SPECIAL PROBLEMS. 

Anyone is at liberty to correspond with the Laboratory about particu- 
lar problems dealing with the utilization of wood and will receive answers 
based on whatever information is available on the subject. The staff 
of the Laboratory is also available for consultation work, provided the 
solution of the problem under consideration will further its general 
research work, or has direct bearing upon it. 

Personal visits to the Laboratory for consultation have proved ver\' 
satisfactory. 

The Laboratory may, on request, examine the methods of individuals 
or companies used in handling forest products and prepare plans for 
improving such methods, provided that the purpose is primarily to 
reduce waste and to obtain information of general value to the indus- 
tries concerned. 

COURSES OF INSTRUCTION. 

Two short cooperative courses of instruction are given monthly at the 
Laboratory — one in kiln-drying, the other in boxing and crating. These 
courses are of particular value to superintendents, lumber and produc- 
tion men, and foremen in wood-using plants. The instruction is under 
the supervision of a staff of competent specialists and the enrollment is 
limited to 16 men in each course, so that proper attention may be given 
to individual problems. Priority of application governs admission to 
the courses, and the classes are usually filled for two or three months 
ahead. 

Detailed information concerning any of the work of the Laboratory 
will be gladly furnished. Inquiries should be addressed to the Director, 
Forest Products Laboratory, ]\Iadison, Wis. 

o 



LIBRARY OF CONGRESS 



DDDoa^flmba 



